// You have a total of n coins that you want to form in a staircase shape, where every k-th row must have exactly k coins.
//
// Given n, find the total number of full staircase rows that can be formed.
//
// n is a non-negative integer and fits within the range of a 32-bit signed integer.
//
// Example 1:
//
// n = 5
//
// The coins can form the following rows:
// ¤
// ¤ ¤
// ¤ ¤
//
// Because the 3rd row is incomplete, we return 2.
//
//
//
// Example 2:
//
// n = 8
//
// The coins can form the following rows:
// ¤
// ¤ ¤
// ¤ ¤ ¤
// ¤ ¤
//
// Because the 4th row is incomplete, we return 3.


/**
 * @param {number} n
 * @return {number}
 */
var arrangeCoins = function(n) {
    return Math.floor(X = (Math.sqrt(8 * n + 1) - 1)/ 2);
};
